Conventionally, acoustic generators that use a piezoelectric element have been known (for example, see Patent Literature 1). The acoustic generators vibrate a vibration plate by applying a voltage to the piezoelectric element attached to the vibration plate and vibrating the piezoelectric element, and output sound by using resonance of the vibration positively.
The acoustic generators can use a thin film such as a resin film for the vibration plate. This enables the acoustic generators to be reduced in thickness and weight in comparison with common electromagnetic speakers and the like.
When the thin film is used for the vibration plate, the thin film is required to be supported in an evenly tensioned state by being held between a pair of frame members in the thickness direction, for example, in order to obtain excellent sound transduction efficiency.